Rapid Microfluidic Formation of Uniform Patient-Derived Breast Tumor Spheroids.

Breast cancer is a highly complex, heterogeneous, and multifactorial disease that poses challenges for rapid and efficient treatment and development of personalized therapy. Here, we describe a rapid and reliable method to generate three-dimensional (3D) tumor spheroids in vitro that recapitulate an individual patient's tumor for testing treatments. By employing droplet microfluidics and scaffold materials, tumor cells were encapsulated into a large number of Matrigel-in-oil droplets with precise control over cell numbers and components per droplet. After removal of the oil, large numbers of uniform tumor spheroids were formed within a few hours via Matrigel-supported cell self-assembly. Our microfluidic technique produces uniform-sized tumor spheroids in less than 1 day. This method was used to reproducibly and rapidly generate uniform-sized tumor spheroids derived from patients' breast tumor tissues. As a proof-of-concept application, this method was used to quickly evaluate cancer treatments. We demonstrated that our microfluidic patient-derived tumor cultures not only preserve the genetic characteristics of the original tumor tissue but also provide heterogeneous responses to targeted therapies within 2 days. We believe this method will enable a timely and reliable 3D in vitro culture model, which may be applicable to personalized treatment prediction, drug discovery, and toxicity testing.